In an interview with Bob Schieffer that aired today on the CBS news program “Face the Nation,” Defense Secretary Leon E. Panetta and Joint Chiefs Chairman Army Gen. Martin E. Dempsey said while the U.S. government prefers to peacefully resolve friction with Iran, the department closely monitors Iran’s nuclear program and actions affecting the Strait of Hormuz.

“We know that they’re trying to develop a nuclear capability, and that’s what concerns us,” Panetta said. “Our red line to Iran is: do not develop a nuclear weapon.”

The secretary noted all options to counter Iran, including military action, remain on the table.

“But the responsible thing to do right now is to keep putting diplomatic and economic pressure on them to force them to do the right thing, and to make sure they do not make the decision to proceed with the development of a nuclear weapon,” he said.

U.S. sanctions against Iran date to 1979, when an executive order froze Iranian assets in the United States in response to Iranian students’ hostage taking at the U.S. embassy in Tehran.

U.S. sanctions increased with a 1984 order limiting arms sales and prohibiting international loans to Iran. A 1987 executive order banned imports of Iranian-origin goods and services in response to aggressive action against shipping in the Persian Gulf.

Responding to Iran’s support of international terrorism and pursuit of weapons of mass destruction, the United States imposed further sanctions in 1995, barring U.S. involvement with petroleum development in Iran.

Additional sanctions in 1997, 2008 and 2010 limited U.S. investment, fund transfers and food trade with Iran. The 2012 National Defense Authorization Act imposes sanctions against Iran’s central bank, affecting Iranian oil exports to nations that do business with the United States.

The UN Security Council has imposed four rounds of economic sanctions against Iran, most recently in 2010.

Panetta said the international strategy toward Iran -- “to try to convince [them] that if they want to do what’s right, they need to join the international family of nations and act in a responsible way -- is working.”

The international community should continue working together on issues relating to Iran, he said.

“We have common cause here,” Panetta said. “We’re not interested in them developing a nuclear weapon; we are not interested in them proliferating violence throughout that region; we are not interested in them trying to assist in terrorism; we are not interested in them trying to destabilize governments in that region or anyplace else.”

If Iran takes the step to develop a nuclear weapon, he added, “They’re going to get stopped.”

Iran developing a nuclear weapon or blocking the Strait of Hormuz both represent “red lines” for the United States, the secretary said. The Iranian government has threatened to prohibit or restrict international maritime transit through the strait, which connects the Gulf of Oman and the Persian Gulf, and is the only ocean access for most Persian Gulf nations.

Iran could close the strait for a time, Dempsey said, but the United States has the ability to reopen the waterway.

“Yes, they can block it,” the chairman said. “We’ve described that as an intolerable act, and it’s not just intolerable for us, it’s intolerable to the world. But we would take action and reopen the straits.”

Dempsey said his job as the nation’s senior military officer is to ensure U.S. forces are prepared for any action they are ordered to carry out.

“My responsibility [regarding Iran] is to encourage the right degree of planning, to understand the risks associated with any kind of military action, [and] in some cases to position assets to provide those options in a timely fashion,” he said. “And all those activities are going on. “